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If you use ULTIMATE for a Head Gasket repair and it and it fails to fix the leak get in touch to find out about our money back guarantee. For all our other brands if you have a repair that subsequently fails contact us for a replacement bottle.
Reviews 493
Khaleel Hussain
Oct 16,2019Not going to jump on and say K seal does not work because it didn't quite repair the leak on my peugot 307 1.6hdi but again not sure if I was supposed to use it for that kind of leak Had water dripping from under the engine however was losing coolant faster than it was dripping anyway it was the water intake plastic pipe that connects from the water pump to the thermostat. Decided to use K Seal plus or extreme (the red bottle) to my surprise the leak was fixed took it for a spin and everything seemed good. Later on that day as I was going uphill it ended up blowing the plastic housing off where the Initial leak was. Now to my experience I could see the K seal actually doing its job and trying to attempt and fix the leak only it may not have been designed for that specific leak, I have now replaced the pipe. I am still losing water, less but with no visible leak anywhere pressure also seems good and replaced the expansion cap. So now I'm deciding whether to give it another go as I have no visible leak now and think it may be from water pump or a minor head gasket as not getting any oil mixture yet so wanting to give it a shot again. I mean it is a little expensive if it doesn't work or makes anything worse.
Daniel Mills
Oct 11,2019Not impressed and quite angry. Read a lot of great reviews on this. Honda Civic 2004 with just 55k suffering intermittent overheating. Have replaced thermostat, rad cap, waterpump and radiator with a hole months back and alleviated the overheating to a leak that needing topping up a bit every week and it would run as if no issues. Thought I'd use some of this to see if it was a small gasket leak as suspected. It couldn't do any harm it says, you can leave it in the system. I did so and regret it entirely. It foamed the car coolant system horrendously. I spent three hours continuously flushing and the car still foams and there are still bronze fragments from this sealer pumping around. I get that blown gasket combustion gasses can cause this, but it never did so before. The rate which foam forms on the top of the radiator neck looks more chemical than heat induced. Heat foam would return to water when cooled. This stays as a foam for ages. I'm flushing pure water, this stuff won't come out. I wish I hadn't. Single parent and not enough money to get it fixed let alone a replacement car. Screwed.
Customer
Oct 07,2019I have just put some k-seal in my Range Rover sport as could not find the leak but now still have the leak but have no heating to go with it. I should of listened to all the people that said don't use as more trouble than anything else. As you can see I have received a response from K-Seal however I am unable to read it as there are no actual words contained in it
crow frasard
Oct 07,2019Not sure how to rate this yet could be my own fault or it could be the issue of the head going but I drained my entire system before putting this in however I put it in during the refilling instead of after or before Car is a 04 dodge intrepid with a 3.5l and the issue is exhaust in the cooling system issue stumped me at first seeing as I wasn’t giving off any form of smoke from the tailpipe I changed the thermostat which had been shot and the upper radiator hose along with the lower intake manifold and gaskets (yes I’m basically rebuilding the engine I know) and nothing tried this stuff but it seems the exhaust is so great this stuff can’t even get to the leak no idk if it’s my fault for how I added it or if it’s the fact that I didn’t run the heater when I bled the system but going to do a proper bleeding tomorrow with this in the coolant and hope it moves from the res tank to sealing the issue if that doesn’t work I’m calling first thing in the morning And for the rep who reads this yes it was the ultimate bottle
N s-p
Sep 26,2019Can this product be used on a motorcycle?
Stuart Forbes
Sep 22,2019Hi I've got a 3071.4hdi and it was using water slowly eventually I was having to fill the expantion tank every second day couldn't see wear the leak was but think it was coming from water pump area as the pump is covered by timing belt cover.So read about k seal and gave it a go drove couple of miles and checked checked expantion tank next morning and water level hasn't moved since it has worked this was a week ago so fingers crossed it has done the job would recommend this to anyone with a leak in your car give it a go it worked for me Thank you k seal just hope it keeps on working.
Rob Hendry
Sep 21,2019I had an annoying radiator leak in my beloved Volvo 850. It was taking a litre a day. My friendly local motor spares shop said, this stuff is the business. More expensive than the competition but worth it, he said. I put the stuff in the expansion tank, ticked over for the allotted time beyond full temperature then drove it 3 miles at below 2000rpm (not easy). The following day I did a 10-15 mile round trip, parked up and was shocked to see water dribbling out of the radiator. Terrible considering the leak was more or less invisible before this was bad news indeed! However a day or two later the Niagara impersonation had stopped but the coolant was still going down slightly. I’m thinking of bunging another dose through, another throw of the dice before considering the car’s future.
Russ Masters
Sep 13,2019No other words than 1st Class Product!! Instant peace of mind, I literally watched a coolant leak stop, 500 miles later no leak whatsoever, and no smell of burnt coolant, I know a certain wood stain company have the tag line but.. K-Seal does EXACTLY what says its going to do.
Rio
Sep 10,2019I would give this product a negative if I could. I'm really ticked off!! Beware! We bought this product and used it. first it did not work, then they sent us a second bottle to use, nada, nothing it did not work. We are now replacing our radiator and have other issues that they say were caused by the use of this product. We are now being advised to have a complete coolant flush/ and then drive the darn car for over a 100 miles and see what happens. We have other issues that may be related to the use of this in our car radiator. Apparently it doesn't just stay in the radiator to plug the hole, it migrates and can cause your heater core to fail/ air conditioning to fail/ heating/ and more. I would really think about this long and hard before you do this to your car. If you end up fixing the leak, and then you end up with bigger problems like us, well......But you should read up about this online, there are others who have had a bad experience and ended up paying for it. Much better to just have your radiator replaced.
Corey Higgins
Sep 03,2019My head gasket blew today made it over heat and put water in my oil but the car was still running so I got some k seal and followed the instructions it didn’t work my car is a Vauxhall frontera 2.2i petrol
Matthew Beggarly
Sep 01,2019I'm going to give it a five for now but that may change. I have a 1994 dodge b250 van with a 318 it only has 120,000 miles on it but last week the belt broke and it overheated bad. I put a new belt on sealed a pressure leak that occured in the radiator but feared I also got a head gasket leak. I put in k seal on the recommendation from a trusted mechanic and it worked great for a few weeks. I just took it for a major east coast ride breaking the trip up in 6 250 mile days and started having the problem again. I just added another bottle and hoping for the best.
Steven M. Covington
Sep 01,2019I had the King of Coolant leaks after a water pump repair. Coolant was spurting and pouring from my thermostat housing and I did some digging and found reviews for K Seal. Not gonna lie I was planning on junking my van as a shop wanted $600+ for them to repair it. K Seal STOPPED the leak! I used3 bottles but the leak stopped. Mind you in my situation I also had a lot of coolant loss. 1 week later my cooling system is running better than ever. It may be $15 a bottle but this stuff is worth EVERY penny!!!
Julian
Aug 30,2019I used K Seal Ultimate and it did exactly what it said it would do. It was easy to use and has saved me thousands of pounds in repair costs. A friendly mechanic put my Volvo V50 up on a ramp and diagnosed rusty leaking engine block core plugs. My heart sank as it would have been an engine out of the car job. But one bottle of K Seal fixed the leak. This is such an amazing product.
Ram Kilic
Aug 28,2019I used K Seal in May 2018 following a constant coolant loss issue in my Citroen Xsara Picasso 1.6 petrol, which I believe was a crack somewhere as the emgine oil cap had white deposits ad well as engine running erratically. Within 2 days all of the symptoms disappered and had been running the car trouble free up until yesterday. I checked the coolant level after engine started erratically and noticed a drop in coolant levels. Is it advisable to use another bottle of K Seal? Also, K Seal states that treatment is permanent.
Tara Bradley
Aug 28,2019I chose to use this product after reading the wonderful reviews, i had all the signs of a blown head gasket on my vauxhall astra 1.4 ecotec and so bought the ultimate sealer for £40. I followed all of the instructions and used the car and a few short journeys and finally everything seemed to be ok, but after using it a few times today (again short journeys) the car started to overheat and the coolant expansion tank started to foam up. Looks like my car will now have to be scrapped as I cant afford the head gasket repair.
Shaun
Aug 22,2019Hi there just wondering if it will be okay to put k seal hd into my CAR'S cooling system as I bought the wrong one i have a major leak from bottom of water pump thanks
Mark
Aug 22,2019Had a coolant leak on my 2002 BMW X5 3l diesel garage quoted over £1000 to sort. A friend mentioned about K-Seal so rather than scrap my car I gave it a go! And so far I’ve not lost any coolant and the performance is better! Thanks K-Seal, I love my X5 and I’m so happy that K-Seal seems to have sorted everything!
Yvonne Knowles
Aug 10,2019Hi this is more of a question I left the cap off the expansion tank when filling my water up & the water boiled dry in the expansion tank since got a new cap & topped water back up but ever since been experiencing boiling water in expansion tank I have no creamy residue on my oil cap tried k seal pour & go & still continuing to boil mechanic has told me he’s 99% sure it’s the head gasket & it’s sucking air will k seal ultimate work? Hi thankyou for your response it’s greatly appreciated iv ordered the k seal ultimate through amazon & it’s come today it’s my husbands car he’s going to put it in tomorrow he’s asked can he put it in the expansion reservoir on a Peugeot 207 cc?
The Spring Expert
Jul 21,2019Several years ago, I was in the middle of nowhere in my Land Rover Discovery (deep in the countryside on a long greenlane) when I noticed what looked like dust rising from somewhere in the dashboard. Over the next few minutes the windscreen started to steam up and I realised it wasn't dust, it was steam! I had split the heater matrix. Unfortunately this is buried deep in the dashboard, and isn't a minute job to replace. Asking on the various Land Rover forums have the suggestion to try kseal. Wow... instant fix. Couldn't believe how quickly it fixed it. Roll on several more years and I was planning a trip to Croatia and whilst the kseal repair hadn't caused any issues, I thought I had better "fix it properly" before such a major trip to a hot country. I stripped out the dash, and eventually got to the matrix. The split was huge, but the kseal had repaired it perfectly. Whilst I guess I could have left the original matrix and done the trip to Croatia, I did swap it. In future I would leave it and trust the kseal!
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Oct 18,2019this is the worse stuff ever i had a minor leak on my corsa which i topped up every month i spent £25 and my car now pressurises and has no heating so upset and let down knowing it will cost me soo much money now